configure: Group all arguments at the top of the configure file.

configure.ac

 AC_CONFIG_MACRO_DIR([m4])
 AC_CONFIG_HEADERS([config.h])
 
+dnl ================================================================
+dnl configure arguments
+dnl ================================================================
+
+AC_ARG_WITH([gradle],
+    [AS_HELP_STRING([--with-gradle], [specify the gradle program to use @<:@default=gradle@:>@])],
+    [GRADLE=$with_gradle],
+    [GRADLE=gradle])
+
+AC_ARG_WITH([pcaudiolib],
+    [AS_HELP_STRING([--with-pcaudiolib], [use the pcaudiolib library for audio output @<:@default=yes@:>@])],
+    [])
+
+AC_ARG_WITH([klatt],
+    [AS_HELP_STRING([--with-klatt], [enable the Klatt formant synthesizer @<:@default=yes@:>@])],
+    [])
+
+AC_ARG_WITH([mbrola],
+    [AS_HELP_STRING([--with-mbrola], [enable the MBROLA speech synthesizer @<:@default=yes@:>@])],
+    [])
+
+AC_ARG_WITH([sonic],
+    [AS_HELP_STRING([--with-sonic], [enable the sonic library to speed up the audio @<:@default=yes@:>@])],
+    [])
+
+AC_ARG_WITH([async],
+    [AS_HELP_STRING([--with-async], [enable support for async command processing @<:@default=yes@:>@])],
+    [])
+
+AC_ARG_WITH([extdict-ru],
+    [AS_HELP_STRING([--with-extdict-ru], [use the extended Russian Dictionary file @<:@default=no@:>@])],
+    [])
+
+AC_ARG_WITH([extdict-zh],
+    [AS_HELP_STRING([--with-extdict-zh], [use the extended Mandarin Chinese Dictionary file @<:@default=no@:>@])],
+    [])
+
+AC_ARG_WITH([extdict-zhy],
+    [AS_HELP_STRING([--with-extdict-zhy], [use the extended Cantonese Chinese Dictionary file @<:@default=no@:>@])],
+    [])
+
+AC_ARG_WITH([libfuzzer],
+    [AS_HELP_STRING([--with-libfuzzer], [enable libFuzzer in the fuzzer tests @<:@default=no@:>@])],
+    [])
+
 dnl ================================================================
 dnl Program checks.
 dnl ================================================================
 dnl gradle checks.
 dnl ================================================================
 
-AC_ARG_WITH([gradle],
-    [AS_HELP_STRING([--with-gradle], [specify the gradle program to use @<:@default=gradle@:>@])],
-    [GRADLE=$with_gradle],
-    [GRADLE=gradle])
-
 AC_MSG_CHECKING([for gradle])
 if test -e ${GRADLE} ; then
     AC_MSG_RESULT([${GRADLE}])
 dnl PCAudioLib checks.
 dnl ================================================================
 
-AC_ARG_WITH([pcaudiolib],
-    [AS_HELP_STRING([--with-pcaudiolib], [use the pcaudiolib library for audio output @<:@default=yes@:>@])],
-    [])
-
 if test "$with_pcaudiolib" = "no"; then
     echo "Disabling audio output support via pcaudiolib"
     have_pcaudiolib=no
 dnl Optional compilation checks.
 dnl ================================================================
 
-AC_ARG_WITH([klatt],
-    [AS_HELP_STRING([--with-klatt], [enable the Klatt formant synthesizer @<:@default=yes@:>@])],
-    [])
-
 if test "$with_klatt" = "no" ; then
 	have_klatt=no
 else
 	have_klatt=yes
 fi
 
-AC_ARG_WITH([mbrola],
-    [AS_HELP_STRING([--with-mbrola], [enable the MBROLA speech synthesizer @<:@default=yes@:>@])],
-    [])
-
 if test "$with_mbrola" = "no" ; then
 	have_mbrola=no
 else
 	have_mbrola=yes
 fi
 
-AC_ARG_WITH([sonic],
-    [AS_HELP_STRING([--with-sonic], [enable the sonic library to speed up the audio @<:@default=yes@:>@])],
-    [])
-
 if test "$with_sonic" = "no" ; then
     have_sonic=no
 else
         ])
 fi
 
-AC_ARG_WITH([async],
-    [AS_HELP_STRING([--with-async], [enable support for async command processing @<:@default=yes@:>@])],
-    [])
-
 if test "$with_async" = "no" ; then
 	have_async=no
 else
 dnl Extended dictionary checks.
 dnl ================================================================
 
-AC_ARG_WITH([extdict-ru],
-    [AS_HELP_STRING([--with-extdict-ru], [use the extended Russian Dictionary file @<:@default=no@:>@])],
-    [])
-
 if test "$with_extdict_ru" = "yes" ; then
 	have_extdict_ru=yes
 else
 	have_extdict_ru=no
 fi
 
-AC_ARG_WITH([extdict-zh],
-    [AS_HELP_STRING([--with-extdict-zh], [use the extended Mandarin Chinese Dictionary file @<:@default=no@:>@])],
-    [])
-
 if test "$with_extdict_zh" = "yes" ; then
 	have_extdict_zh=yes
 else
 	have_extdict_zh=no
 fi
 
-AC_ARG_WITH([extdict-zhy],
-    [AS_HELP_STRING([--with-extdict-zhy], [use the extended Cantonese Chinese Dictionary file @<:@default=no@:>@])],
-    [])
-
 if test "$with_extdict_zhy" = "yes" ; then
 	have_extdict_zhy=yes
 else
 dnl libFuzzer checks.
 dnl ================================================================
 
-AC_ARG_WITH([libfuzzer],
-    [AS_HELP_STRING([--with-libfuzzer], [enable libFuzzer in the fuzzer tests @<:@default=no@:>@])],
-    [])
-
 if test "$with_libfuzzer" = "yes" ; then
 	have_libfuzzer=yes
 else